Air or sea? What actually changes when Kenyan roses travel by water

The scale, before anything else

Sea freight is real but small, and growing from a low base. Research published by Wageningen Food & Biobased Research in 2023 records:

Note the frequency line, because it decides more than it looks. Three departures a week against three services a day is not a small difference in convenience; it is the difference between a missed connection costing you days and costing you hours.

The finding that should change how you think about it

The intuitive objection to sea freight is that thirty days must ruin a flower. Measured properly, that is not what the research says.

The same temperature sum — and therefore, potentially, the same remaining vase life.

The variable is not the days. It is whether the cold chain actually holds at half a degree for thirty days. Air is forgiving because it is short. Sea is unforgiving because it is long — a chain that drifts warm for a week on a two-day journey is impossible; on a thirty-day journey it is a Tuesday.

So the question to ask a supplier is not "isn't sea freight worse?" It is "what temperature is held, where is it measured, and what happens when it is not."

The hard limit, and it is quantified

Sea freight has a cliff rather than a slope, and the research puts a number on it:

">35 days means serious Botrytis, for each additional day 3–4% extra"

Observed waste on sea-freighted roses runs at 10–12%.

Thirty-five days is not far from a thirty-five-day nominal transit. That is the whole risk in one sentence: the schedule has very little slack before quality falls away quickly, and the delay is the thing nobody controls.

The research also notes that outcomes differ between cultivars and between growers, and probably with greenhouse conditions and with the season. Which means sea-freight performance is not a property of "Kenyan roses" — it is a property of a specific variety from a specific farm in a specific month, and should be specified that way.

Why the ship is late, and why that will not change soon

The reliability problem is structural, and the researchers state it more bluntly than a carrier would:

"200 reefers which want to have a fixed arrival date are not important enough compared to the 20,000 containers on the ship"

Flowers are a rounding error on a container vessel. Add the risk of a missed connection or power problems at the transhipment point, and the arrival date in Rotterdam is not reliable. The research is explicit that sea freight still needs a backup by air.

Read that as a cost, not a footnote. If your programme needs air standing behind sea, you are carrying part of both.

The commercial arithmetic most promotion leaves out

That is the sentence to sit with. Sea freight is roughly a quarter cheaper to move and loses most of that advantage to product that does not arrive saleable. The researchers go further and suggest the price gap should be wider than it is, precisely to fund buying extra stems against unreliable transport.

It also changes what you have to commit to:

• A two-month forecast instead of two weeks, because of the longer lead time.
• On direct-supply tenders, a substantial sea share — around 30% — is reported as needed to win retail business, which makes it a commercial requirement rather than a logistics preference.
• On the grower's side, sea demands a different process, and a couple of pallets a week does not justify it. The research suggests a grower needs to be above roughly 20% sea freight for the investment to make sense.

Mainstream, predictable product is where this works. The research says so directly: master planning and rolling stock suit it. Anything date-critical does not.

Where sea freight is simply the wrong answer

Valentine's Day, International Women's Day, either Mother's Day, or any fixed-date event.

A thirty-five-day transit with an unreliable arrival date, a quality cliff at thirty-five days, and three sailings a week cannot serve a deadline that does not move. That is not a criticism of sea freight; it is a description of what it is for. The peak calendar is set out here — three global peaks fall inside about fourteen weeks, and none of them will wait for a ship.

And the reason the question will not go away

Sea freight is reported to cut carbon by around 80% against air. The research notes air may close some of that gap with bio-ethanol, and that an EU limit on CO₂ per kilogram of imported product would be a game changer.

So the pressure to move volume onto water is not really a cost argument. It is a carbon argument with a cost argument attached, and if retail carbon demands harden, the trade-offs on this page become a buyer's problem whether or not the economics have improved.